Microbe of the Month: A few drops of poison had her talking again: The toxin that causes botulism also has beneficial uses, says Bernard Dixon

IT BEGAN as a respiratory infection, which left the 32-year-old travel agent somewhat hoarse. Then, as the months went by, she found that she could not control her voice properly. There were strange and frequent changes in pitch, and breaks in delivery.

The woman was offered speech therapy but without any lasting benefit. Next she tried psychological counselling, as her doctor suspected that the mysterious speech disorder could have resulted from the stresses of her job and recent divorce. This too failed to bring relief from the distressing affliction, which worsened over the next two years.

Although the condition then began to stabilise, it did not abate. During the following three years, the patient experimented with a wide range of possible remedies, from hypnosis and acupuncture to tranquillisers and other drugs. But nothing seemed to work, and she was forced to take up a new job in which she was not required to speak. Gradually, she reduced her social contacts, became chronically depressed and was given long-term medication.

At this point, the woman's psychiatrist referred her to the National Institutes of Health in Bethesda, Maryland. There, a laryngologist used a fibre optic endoscope to peer into the patient's throat, and discovered that some of the muscles responsible for speech were having uncontrollable spasms. Although they looked perfectly normal, the vocal cords showed spasmodic contractions that were causing the weird gaps and changes in pitch in the woman's voice.

It was this discovery that immediately suggested a potential panacea - botulinum A toxin, one of the most poisonous substances known. Injected in tiny quantities into the appropriate muscles, it relieved the woman's symptoms and greatly reduced the effort she required to speak. Her voice was no longer interrupted, and examination of her vocal cords showed that they were behaving normally.

Although the condition began to recur three months later, it stabilised without becoming as severe as before, and responded to further injections of toxin. Subsequent treatment was required but with decreasing doses at increasing intervals of time, and the woman was able to return to work as a travel agent and rebuild her social life.

Bizarre though the story may appear, it represents just one of many successes over the past decade in using an otherwise extremely dangerous microbial product for therapeuti cpurposes.

Made by the bacterium Clostridium botulinum, botulinum A toxin is responsible for botulism, a rare and often fatal form of food poisoning. It works by stopping nerve endings releasing acetylcholine, a chemical that communicates with other nerve endings. This weakens the muscles controlled by those nerves, preventing them from contracting.

The initial consequences, in untreated botulism, are blurred or double vision, followed by increasing difficulty in swallowing and breathing.

Dr Alan Scott, working at the Smith Kettlewell Eye Research Foundation in San Francisco, was the first to realise that this potentially fatal action might be exploited to beneficial effect, first of all in the treatment of squint. He reasoned that a minute dose of botulinum A toxin would relax the over-reacting muscles responsible for the abnormal position of the eye. It worked. Patients were helped, the principle was vindicated, and this approach to squint is now firmly established, sometimes combined with surgery.

However, since first being used in the UK in 1983, botulinum A toxin has turned out to be even more useful for other conditions characterised by dystonia (ie, uncontrollable muscle spasms). They include focal dystonias, which affect a limb or other part of the body, and spasmodic torticollis, which paralyses the neck muscles, causing the patient's head to twist to one side, forwards or backwards.

One of the most distressing dystonias is blepharospasm. Sufferers blink uncontrollably and may be unable to prevent their eyes from remaining permanently closed. There are more than 4,000 known cases of blepharospasm in the UK and at least 20,000 victims of all types of dystonia.

Botulinum A toxin, now marketed by Porton Products Ltd, of Porton Down, Wiltshire, has already helped thousands of individuals incapacitated by muscle spasms that were hitherto untreatable, often painful, and devastating in terms of employment, leisure activities and social life. For example, it relieves the symptoms totally in almost a third of patients with blepharospasm.

Similarly encouraging results have been reported in conditions ranging from writer's cramp and musicians' dystonias to golfer's 'yips' and dart player's cramp. Very recently, work at the Columbia-Presbyterian Medical Center, New York, indicated that the toxin can be used to improve

the speech of some people who stutter.

For the moment, botulinum A toxin is relatively expensive (about pounds 100 per injection for blepharospasm). Injections sometimes need to be repeated three or four times a year. And it is possible that patients may develop antibodies that reduce the effectiveness of the treatment.

Nevertheless, the advances of the past decade, the continuing extension of the range of conditions amenable to this approach and current research on other types of botulinum toxin indicate that Clostridium botulinum will play a major role in the future of human medicine.

Suggested Topics
Life and Style
“What is it like being a girl?” was the question on the lips of one inquisitive Reddit user this week
News
peopleDave Legeno, the actor who played werewolf Fenrir Greyback in the Harry Potter films, has died
Arts and Entertainment
Armando Iannucci, the creator of 'The Thick of It' says he has
tvArmando Iannucci to concentrate on US show Veep
Life and Style
beauty
PROMOTED VIDEO
Sport
Luis Suarez looks towards the crowd during the 2-1 victory over England
transfers
Life and Style
Swimsuit, £245, by Agent Provocateur
fashion

Diving in at the deep end is no excuse for shirking the style stakes

Sport
German supporters (left) and Argentina fans
world cup 2014Final gives England fans a choice between to old enemies
Arts and Entertainment
A still from the worldwide Dawn of the Planet of the Apes trailer debut
film
News
peopleMario Balotelli poses with 'shotgun' in controversial Instagram pic
News
A mugshot of Ian Watkins released by South Wales Police following his guilty pleas
peopleBandmates open up about abuse
Sport
Basketball superstar LeBron James gets into his stride for the Cleveland Cavaliers
sportNBA superstar announces decision to return to Cleveland Cavaliers
Sport
Javier Mascherano of Argentina tackles Arjen Robben of the Netherlands as he attempts a shot
world cup 2014
Arts and Entertainment
The successful ITV drama Broadchurch starring David Tenant and Olivia Coleman came to an end tonight
tv
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Sport
Four ski officials in Slovenia have been suspended following allegations of results rigging
sportFour Slovenian officials suspended after allegations they helped violinist get slalom place
News
14 March 2011: George Clooney testifies before the Senate Foreign Relations Committee during a hearing titled 'Sudan and South Sudan: Independence and Insecurity.' Clooney is co-founder of the Satellite Sentinel Project which uses private satellites to collect evidence of crimes against civilian populations in Sudan
people
Arts and Entertainment
Balaban is indirectly responsible for the existence of Downton Abbey, having first discovered Julian Fellowes' talents as a screenwriter
tvCast members told to lose weight after snacking on set
Life and Style
More than half of young adults have engaged in 'unwanted but consensual sexting with a committed partner,' according to research
tech
Life and Style
A binge is classed as four or more alcoholic drinks for women and five or more for men, consumed over a roughly two-hour period
tech
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

JavaScript Developer (Angular, Web Forms, HTML5, Ext JS,CSS3)

£40000 - £45000 per annum + Benefits + Bonus: Harrington Starr: JavaScript Dev...

BC2

£50000 - £70000 per annum: Harrington Starr: Business Analyst Consultant (Fina...

SAP Data Migration Consultant

competitive: Progressive Recruitment: My client, a FTSE 100 organisation are u...

Programme Support, Coms, Bristol, £300-350p/d

£300 - £350 per day + competitive: Orgtel: My client, a leading bank, is curre...

Day In a Page

A History of the First World War in 100 Moments: Peace without magnanimity - the summit in a railway siding that ended the fighting

A History of the First World War in 100 Moments

Peace without magnanimity - the summit in a railway siding that ended the fighting
Scottish independence: How the Commonwealth Games could swing the vote

Scottish independence: How the Commonwealth Games could swing the vote

In the final part of our series, Chris Green arrives in Glasgow - a host city struggling to keep the politics out of its celebration of sport
Out in the cold: A writer spends a night on the streets and hears the stories of the homeless

A writer spends a night on the streets

Rough sleepers - the homeless, the destitute and the drunk - exist in every city. Will Nicoll meets those whose luck has run out
Striking new stations, high-speed links and (whisper it) better services - the UK's railways are entering a new golden age

UK's railways are entering a new golden age

New stations are opening across the country and our railways appear to be entering an era not seen in Britain since the early 1950s
Conchita Wurst becomes a 'bride' on the Paris catwalk - and proves there is life after Eurovision

Conchita becomes a 'bride' on Paris catwalk

Alexander Fury salutes the Eurovision Song Contest winner's latest triumph
Pétanque World Championship in Marseilles hit by

Pétanque 'world cup' hit by death threats

This year's most acrimonious sporting event took place in France, not Brazil. How did pétanque get so passionate?
Whelks are healthy, versatile and sustainable - so why did we stop eating them in the UK?

Why did we stop eating whelks?

Whelks were the Victorian equivalent of the donor kebab and our stocks are abundant. So why do we now export them all to the Far East?
10 best women's sunglasses

In the shade: 10 best women's sunglasses

From luxury bespoke eyewear to fun festival sunnies, we round up the shades to be seen in this summer
Germany vs Argentina World Cup 2014: Lionel Messi? Javier Mascherano is key for Argentina...

World Cup final: Messi? Mascherano is key for Argentina...

No 10 is always centre of attention but Barça team-mate is just as crucial to finalists’ hopes
Siobhan-Marie O’Connor: Swimmer knows she needs Glasgow joy on road to Rio

Siobhan-Marie O’Connor: Swimmer needs Glasgow joy on road to Rio

18-year-old says this month’s Commonwealth Games are a key staging post in her career before time slips away
The true Gaza back-story that the Israelis aren’t telling this week

The true Gaza back-story that the Israelis aren’t telling this week

A future Palestine state will have no borders and be an enclave within Israel, surrounded on all sides by Israeli-held territory, says Robert Fisk
A History of the First World War in 100 Moments: The German people demand an end to the fighting

A History of the First World War in 100 Moments

The German people demand an end to the fighting
New play by Oscar Wilde's grandson reveals what the Irish wit said at his trials

New play reveals what Oscar Wilde said at trials

For a century, what Wilde actually said at his trials was a mystery. But the recent discovery of shorthand notes changed that. Now his grandson Merlin Holland has turned them into a play
Can scientists save the world's sea life from

Can scientists save our sea life?

By the end of the century, the only living things left in our oceans could be plankton and jellyfish. Alex Renton meets the scientists who are trying to turn the tide
Richard III, Trafalgar Studios, review: Martin Freeman gives highly intelligent performance

Richard III review

Martin Freeman’s psychotic monarch is big on mockery but wanting in malice